The subject matter of the present disclosure broadly relates to the art of suspension systems and, more particularly, to a gas suspension member adapted to interconnect with a gas transmission line as well as a method of forming such a gas suspension member.
The subject matter of the present disclosure finds particular application in association with gas suspension members used on suspension systems of vehicles, and will be discussed herein with particular reference thereto. However, it will be appreciated that the subject gas suspension member and method are equally applicable for use in other applications and environments, and are not intended to be in any way limited to use in the applications discussed herein, which are merely exemplary.
Gas suspension members having an inlet for connecting a gas transmission line are generally well known. One example of such a gas suspension member is disclosed in U.S. Pat. No. 6,145,894 to Myers, which is hereby incorporated herein by reference in its entirety.
Gas suspension members have been commonly used in a wide variety of applications, such as vehicle suspension systems, for example, with great success. Gas suspension members for vehicle suspension systems are available in a wide variety of types, styles and configurations, including those with rigid end members as well as designs with flexible end walls. Though numerous advantages exist with the regard to the use of gas suspension members in vehicle suspension systems, there are also areas for improvement, such as reducing maintenance or increasing the ease of installation, for example.
One such opportunity for improvement exists in gas suspension members that have flexible end walls. Vehicle suspension systems by their very nature are designed to permit dynamic movement between various portions and components of the vehicle. As such, it is common for parts associated therewith to be repeatedly flexed or stressed. Gas suspension members are one example of such parts, and those having flexible end walls are typically well adapted for such flexing action.
Connection of such fluid suspension members to a fluid supply is typically accomplished through a fitting installed on the end wall of the fluid suspension member, as is shown in the Myers '894 patent, for example. The fitting, which is commonly made from metal, forms a fluid-tight seal with the flexible end wall on which it is installed. Repeated flexing of the end wall, however, can, in some cases, cause the flexible material surrounding the fitting to become separated from the connector fitting. This typically compromises the seal around the connector fitting, resulting in pressurized gas loss, which can reduce performance and/or efficiency of the suspension system among other problems.
One significant source of separation is caused by inflation-induced stresses along the flexible wall on which the fitting is installed. That is, the opposing end walls of the gas suspension member become somewhat crowned or dome-shaped due to the pressure within the gas suspension member. The nature of the deflection and the typical positioning of the fitting on the end wall can cause any forces that would otherwise act to seal against the fitting to be overcome. This can undesirably result the loss of integrity of the fluid-tight seal formed around the fitting.
Various arrangements have been employed to improve the interconnection between the connector fitting and the flexible end wall. One method has been to mold the connector fitting into the part during the manufacture of the flexible wall. Unfortunately, the mechanical properties of the wall material alone have been found to be insufficient to consistently withstand the separation stresses discussed above. As such, even with residual compressive stresses attributable to the over-molding process, this connection method has not been successful on a consistent basis. Another method that has been used to improve the interconnection between the connector fitting and the surrounding flexible material includes the use of adhesive. Though this arrangement significantly strengthens the interconnection between the connector fitting and the flexible wall, the adhesive and process of applying the same cause undesirable increases in manufacturing costs among other disadvantages.
Another example of a gas suspension member that has been successful in improving the interconnection between a connector fitting and the flexible end wall is disclosed in U.S. Pat. No. 7,270,317 to Leonard, which is hereby incorporated herein by reference in its entirety. Broadly speaking, the '317 patent discloses an arrangement in which a groove is formed along the flexible end wall of the gas suspension member adjacent a portion of the end wall that sealingly engages the connector fitting. This arrangement permits the end wall to flex while the transmission of separation-causing forces to the portion of the end wall that sealingly engages the connector fitting is minimized or at least reduced.
Notwithstanding the success of the arrangement in the '317 patent as well as that of other known devices, it is remains desirable to pursue the development of gas suspension members and methods of manufacturing the same that further contribute to the art of gas spring devices.